Department of Chemistry and Institute for Soldier Nanotechnologies, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts, 02139, USA.
Physical Science and Engineering Division, King Abdullah University of Science and Technology, KAUST, Thuwal, 23955-6900, Saudi Arabia.
Angew Chem Int Ed Engl. 2017 Nov 6;56(45):14066-14070. doi: 10.1002/anie.201707491. Epub 2017 Oct 4.
Carbon monoxide (CO) outcompetes oxygen when binding to the iron center of hemeproteins, leading to a reduction in blood oxygen level and acute poisoning. Harvesting the strong specific interaction between CO and the iron porphyrin provides a highly selective and customizable sensor. We report the development of chemiresistive sensors with voltage-activated sensitivity for the detection of CO comprising iron porphyrin and functionalized single-walled carbon nanotubes (F-SWCNTs). Modulation of the gate voltage offers a predicted extra dimension for sensing. Specifically, the sensors show a significant increase in sensitivity toward CO when negative gate voltage is applied. The dosimetric sensors are selective to ppm levels of CO and functional in air. UV/Vis spectroscopy, differential pulse voltammetry, and density functional theory reveal that the in situ reduction of Fe to Fe enhances the interaction between the F-SWCNTs and CO. Our results illustrate a new mode of sensors wherein redox active recognition units are voltage-activated to give enhanced and highly specific responses.
一氧化碳（CO）与血红素蛋白中的铁中心结合时会取代氧气，导致血氧水平降低和急性中毒。利用 CO 与铁卟啉之间的强特异性相互作用进行捕获，为高选择性和可定制的传感器提供了可能。我们报告了一种电化学生物传感器的开发，该传感器包含铁卟啉和功能化单壁碳纳米管（F-SWCNTs），对 CO 的检测具有电压激活敏感性。栅极电压的调制为传感提供了一个预测的额外维度。具体来说，当施加负栅极电压时，传感器对 CO 的灵敏度显著增加。剂量计传感器对 ppm 级别的 CO 具有选择性，并且在空气中也能正常工作。紫外/可见光谱、差分脉冲伏安法和密度泛函理论表明，Fe 的原位还原增强了 F-SWCNTs 与 CO 之间的相互作用。我们的结果说明了一种新的传感器模式，其中氧化还原活性识别单元被电压激活，从而产生增强的、高度特异性的响应。
